Conventional search engines receive a search query from a user and execute a search against a global index. Such conventional search engines typically use one or more conventional methods for performing a search. For example, one known method, described in an article entitled “The Anatomy of a Large-Scale Hypertextual Search Engine,” by Sergey Brin and Lawrence Page, assigns a degree of importance to a document, such as a web page, based on the link structure of the web. The search results are often presented in a list format, including article identifiers and brief snippets about the documents in a web page that can be resized.
A user may also have access to other information stored on the user's local machine or on other storage media accessible via a network. Typically, when searching for information using conventional means, a user enters an explicit search query that comprises keywords and the query is executed against either a global or a local index. The query may also be generated as an implicit query. The information found is output to the user as a result set.
Some conventional search systems allow a user to search by categories. For example, the Google™ search engine allows a user to search using categories by selecting the “Directory” (Google Inc., Mountain View, Calif.; www.google.com). The Yahoo!® search engine allows a user to search by categories, either by selecting a category or by entering an explicit query and being presented with one or more categories in the result set (Yahoo! Inc., Sunnyvale, Calif.; www.yahoo.com). The categories utilized by both of these search engines are static and are edited manually.
Other conventional systems provide simplistic categorization. For example, conventional e-mail systems provide the user with the capability of defining message-handling rules. A rule may specify, for example, that any incoming mail message with “News” in the subject be refilled to a news sub-folder within the user's inbox. Such rules are typically defined manually by the user or by an e-mail administrator.